export const getmark = () => {
  const setWatermark = (str: any) => {
    const id = "1.23452384164.123412416";
    if (document.getElementById(id) !== null)
      document.body.removeChild(document.getElementById(id)!);
    //创立一个画布
    const can = document.createElement("canvas");
    //设置画布的长宽
    can.width = 225;
    can.height = 180;
    const cans = can.getContext("2d")!;
    //旋转视点
    cans.rotate((-15 * Math.PI) / 180);
    cans.font = "18px Vedana";
    //设置填充绘画的颜色、突变或者形式
    cans.fillStyle = "rgba(200, 200, 200, 0.40)";
    //设置文本内容的当时对齐方式
    cans.textAlign = "left";
    //设置在制作文本时使用的当时文本基线
    // cans.textBaseline = "Middle";
    //在画布上制作填色的文本（输出的文本，开端制作文本的X坐标方位，开端制作文本的Y坐标方位）
    cans.fillText(str, can.width / 8, can.height / 2);
    const div = document.createElement("div");
    div.id = id;
    div.style.pointerEvents = "none";
    div.style.top = "0px";
    div.style.left = "0px";
    div.style.position = "fixed";
    div.style.zIndex = "999";
    div.style.width = document.documentElement.clientWidth + "px";
    div.style.height = document.documentElement.clientHeight + "px";
    div.style.background =
      "url(" + can.toDataURL("image/png") + ") left top repeat";
    document.body.appendChild(div);
    return id;
  };

  // 该办法只允许调用一次
  const watermark = (str: string) => {
    let id = setWatermark(str);
    setInterval(() => {
      if (document.getElementById(id) === null) id = setWatermark(str);
    }, 500);
    window.onresize = () => setWatermark(str);
  };
  return { watermark };
};
